首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 15 毫秒
1.
2.
近年来对溶剂革取过程中有机相形成微乳状液的研究正引起人们的重视同,我们曾用付里叶变换红外光谱法研究过钢皂及钾皂2一乙基已基股酸单·2一乙基已基酯(简写为NaA及KA下同)加水形成微乳状液的过程,观察到P二0,P-0-C,P-0-HH-0-H和0-H等基团吸收谱带频率或强度的变化[‘剑.本文进一步对#、销和钾三种碱金属皂化2一乙基已基胁酸单一2一乙基已基酯有机相微乳状液的形成及其红外光谱作深入研究.1实验部分五.1样品的制备问将金属捏、销和钾各置于2一乙基巴基磷酸单一2一乙基已基酯(以HA表示,下同)一正庚烷中加热回流…  相似文献   

3.
The demonized water was added to the alkali metal salts of 2-ethythexyl phosphonic acid mono 2-ethylhexyl ester (HA) to form microemulsion of W/O type. The maximum contents of H2O in these systems reached up to the mole ratio (H2O/MA+HA) of 6.5(Li), 12 (Na) and 66 (K), respectively. They are stable when the temperature is lower than 65℃ and no water separation was observed in the ultracentrifuge under 30000r?min-1. Their electrical conductance and infrared spectra in the range of 800-4000cm-1 were studied. The variation of stretching absorption peaks of P=O, P-O-C and P-O-H and their oscillator strengths with the amount of H2O added have been recorded.  相似文献   

4.
The effect of glycerol on both micellar formation and the structural evolution of the sodium dodecyl sulfate (SDS) aggregates in the context of the action mechanism of the cosolvent has been studied. The critical micelle concentration and the degree of counterion dissociation of the surfactant over a temperature range from 20°C to 40°C were obtained by the conductance method. The thermodynamic parameters of micellization were estimated by using the equilibrium model of micelle formation. The analysis of these parameters indicated that the lower aggregation of the surfactant is mainly due to a minor cohesive energy of the mixed solvent system in relation to the pure water. The effect of glycerol on the mean aggregation number of the micelles of SDS was analyzed by the static quenching method. It was found that the aggregation number decreased with the glycerol content. This reduction in the micellar size seems to be controlled by an increase in the surface area per headgroup, which was ascribed to a participation of glycerol in the micellar solvation layer. Studies on the micropolarity of the aggregates, as sensed by the probe pyrene, indicated that this microenvironmental parameter is almost unaffected by the presence of glycerol in the mixture. However, an increase in the micellar microviscosity at the surface region was observed from the photophysical behavior of two different probes, rhodamine B and auramine O. These results suggest a certain interaction of the cosolvent in the micellar solvation of SDS micelles.  相似文献   

5.
测定了在30℃、总离子强度为0.1m时不同比例混合的十烷基硫酸钠(C10SNa)-全氟辛酸钠(7CFNa)在四氯乙烯-水界面的界面张力,研究混合溶液的界面性质及胶团形成,结果表明:(1)7CFNa与C10SNa在混合溶液中,基本上各自独立形成胶团;(2)混合表面活性剂在四氯乙烯-水界面上的吸附与在正庚烷-水界面上吸附规律相同;(3)测定C10SNa、7CFNa在不同油-水界面上的界面张力,证实碳氟链与碳氯链之间具有“互憎性”。  相似文献   

6.
The thermodynamic formation constants of N-(alkyl)-2- and/or 3-mercaptoacetamides complexes with dimethyl-, diethyl-, and n-dibutyltin(IV) cations have been determined potentiometrically in a dioxane-water mixture (75% v/v) at 30 ± 0.1°C in μ = 0.1 M NaCl using the Irving-Rossotti method and refined by the least-squares method. The basicity of the ligands follows the order C2H5NHCOCH2SH > n-C3H7NHCOCH2SH > n-C4HgNHCOCH2SH > C2H5NHCOCH2CH2SH > n-C3H7NHCOCH2CH2SH > n-C4Hg- NHCOCH CH SH. For each ligand the stability order of dialkytin(IV) complexes decreases as follows: [Me2Sn(IV)]2+ >[Et Sn(IV)]2+ > [n-Bu2Sn(IV)]2+. This order is consistent with the group electronegativities of [R2Sn(IV)]2+ cations calculated from Sanderson's electronegativity scale.  相似文献   

7.
JPC – Journal of Planar Chromatography – Modern TLC - Quinolones, because of their hydrophilic (amphiionic) character, are strongly adsorbed by silica even from polar solvents. It has...  相似文献   

8.
Soy oil microemulsions has been optimized for systems made of phosphated oleyl ether 3EO as surfactant, oleic acid, diethyleneglycol monoethyl ether, and water. The soy oil solubilization has been estimated as a function of different ratios between surfactant/oleic acid (5/95, 10/90, 15/85, and 20/80) and water/glycol (4/1, 2/1, 1/1, 1/2, and 1/4). The maximum simultaneous solubilization of soy oil and hydrophilic phase (water plus glycol) in ratios 3/1, 1/1, and 1/3 (besides the 1/0 and 0/1) was considered. In order to display the widest microemulsion area, the better ratios surfactant/oleic acid were 10/90, 15/85, and 20/80 when water and glycol ratios were 1/2 and 1/4. For these systems, the transition between W/O, bicontinuous and O/W microemulsions were followed through electrical conductivity changes.  相似文献   

9.
以1,3-丙二醇为起始原料,经羟甲基化、溴代和硝化反应制得1-甲氧基-3-硝基丙烷(4);4与马来酸二乙酯的缩和产物通过钯炭催化氢化合成了新化合物2-(3-甲氧基丙基)-琥珀酸二乙酯,产率90%,其结构经1H NMR和HR-MS表征.  相似文献   

10.
CnNCl和SDS在水溶液中的相互作用;滴定式微量热法; 烷氧基羟丙基三甲基氯化铵; 十二烷基硫酸钠;胶束;疏水作用  相似文献   

11.
合成了N-十二烷基-N-(2-羟乙基)-N,N-二甲基溴化铵、N-十四烷基-N-(2-羟乙基)-N,N-二甲基溴化铵和N-十六烷基-N-(2-羟乙基)-N,N-二甲基溴化铵等3个季铵盐阳离子表面活性剂. 研究了它们以及N-十六烷基-N,N,N-三甲基溴化铵(CTAB)与阴离子表面活性剂十二烷基硫酸钠(SDS)复配系统在313.15 K时的双水相行为. 复配系统在两个非常狭窄的区域能形成双水相, 两相区近似以等摩尔线为中心对称分布, 随着阳离子表面活性剂碳链长度的增长, 富含阳离子表面活性剂的双水相区向阴阳离子表面活性剂摩尔比减小的方向稍有移动.  相似文献   

12.
The extraction behavior of uranium (VI) from chloride medium with 2-ethylhexyl phosphonic acid mono-2-ethylhexyl ester (PC-88A) in dodecane has been investigated under wide range of conditions. Attempts have been made to establish the extraction mechanism of uranium(VI) with PC-88A. Treatment of the distribution data by slope analysis technique showed the formation of a monomeric complex of the nature [UO2(A2H)2]. Formation of this species was also confirmed by non-linear least square regression of the distribution data to the mathematical expression correlating percentage extraction and acidity. In this investigation attempts have also been made to develop a mathematical model for the system (UO2Cl2-HCl-H2O-PC-88A-dodecane) using experimental data on the distribution of uranium against initial aqueous acidity at different initial metal concentration. The mathematical model D = 37.547±0.223/C i 1/2×[H i ]2 can be used to predict the concentration of uranium in organic as well as in aqueous phases at any initial concentration of uranium [C i ] and initial hydrogen ion concentration [H i ]. The extraction constant (K ex ) has been calculated.  相似文献   

13.
The colloidal stability with respect to temperature of aqueous α-Fe2O3dispersions stabilized with novel poly(vinylmethylether)-block-poly(vinyloxy-4-butyric acid) diblock copolymers was studied by rheological and turbidimetric measurements. Adsorption of the block copolymers provides the particles with a steric barrier due to the nonadsorbing poly(vinylmethylether) (PVME) blocks. Rheological measurements on concentrated (15 vol %) dispersions showed that flocculation occurred near the θ temperature of PVME in water. For the turbidimetric analysis, the fraction of small particles was used at a very low concentration. With these dispersions, flocculation was found at higher temperatures, corresponding to the lower critical solution temperature of the block copolymer used. The particles spontaneously redispersed when a heated and flocculated dispersion was cooled to below the flocculation temperature.  相似文献   

14.
阳离子表面活性剂中相微乳的形成和特性   总被引:10,自引:0,他引:10  
自1943年SdriAn。等人山发现微乳液体系并予以命名以来,对微乳液研究不断深入·微乳液是由油、水、表面活性剂和助表面活性剂组成的各向同性、透明的、热力学稳定的分散体系,微乳液可分为单相微乳液和多相微乳液问.中相微乳液是多相微乳液中,与过剩盐水相和过剩油相达到三相平衡的Winsor皿型微乳液,它在三次采油、日用化工、微环境、酶催化等方面具有特殊重要的应用I‘,‘].近年来对阴离子表面活性剂中相微乳液的形成和特性进行了较多研究[5。8].但对阳离子表面活性剂中相微乳液的研究,目前尚未见报导,本文以澳代十四烷基毗…  相似文献   

15.
本文采用2-乙基己基膦酸单(2-乙基己基)酯(P-507)树脂,使微量稀土元素与钢中的基体元素,铁、钛、钒和钼分离,以 3.0 mol/L盐酸溶液洗脱P-507色层柱上的稀土元素,采用电感耦合等离子体原子光谱法(ICP-AES)同时测定了钢中La、Ce、Pr、Nd、Sm、Y和 Gd 7种微量稀土元素.试样的标准加入回收率99.3%~108%;相对标准偏差小于5%.  相似文献   

16.
Lithium and sodium ion transport through membranes impregnated with a solution of 2-ethylhexyl hydrogen [bis(2-ethylhexyl)amino]methylphosphonate in kerosene has been studied. Factors determining the efficiency and selectivity of membrane extraction have been determined. Introduction of neutral aminomethylphosphine oxide into the membrane phase has been shown to enhance the selectivity for lithium ions.  相似文献   

17.
The phase behavior of the glycerol monooleate (GMO)-sodium cholate-water (or 0.9 wt% NaCl) system has been examined in the solvent-rich part, using small-angle X-ray scattering and conventional methods. Addition of cholate up to 7% of the total amphiphile swells the cubic phase of the binary GMO-water system so that it takes up almost 70% of water in the salt-free case and 55% in salt. With more bile salt the lamellar phase also appears highly swollen (up to 85% in water, 75% in brine). In the salt solution a small isotropic L3-phase region replaces the lamellar phase at a solvent content of about 79%. The lamellar phase can accept only about 0.2 cholate molecule per GMO, in both water and brine, and a phase with globular micelles (L1) follows and dominates the diagram. No threadlike micelles appear in this system. Investigation of the particle structures with cryo-transmission electron microscopy (TEM) in dilute systems (99% solvent) show globular micelles and coexisting vesicles and globular micelles. In the presence of salt, dilution of the L3 phase results in dispersed globular particles with an irregular internal morphology that suggests they are a dispersed L3 phase. These particles coexist with faceted particles having an inner structure giving a hexagonal pattern in projection, suggested to derive from the cubic phase. The cubic phase in the salt-free systems did not give dispersions stable enough for cryo-TEM examination. Copyright 1999 Academic Press.  相似文献   

18.
In this study, Y(2)O(3):Eu luminescent nanoparticles were prepared by precipitation of aqueous yttrium nitrate/europium nitrate solution using ammonium hydroxide in the reverse microemulsions based on polyoxyethylene (5) nonylphenyl ether/polyoxyethylene (9) nonylphenyl ether, cyclohexane, and water. With Eu-doped Y(2)O(3) nanoparticles obtained, particle size, shape, chemical composition, crystalline formation rate, crystallinity, and photoluminescence were measured and compared with those of particles formed by a bulk precipitation method. The nanoparticles synthesized in microemulsion showed a narrow size distribution, spherical shape, fast crystalline formation rate, high crystallinity, and strong photoluminescence. This stronger photoluminescence of particles formed in a microemulsion might be attributed to more densely packed particles with very few voids and higher crystallinity at a relatively low temperature than those synthesized through a bulk precipitation method. Copyright 2000 Academic Press.  相似文献   

19.
Pseudo-ternary phase diagrams have been constructed for the three-component solvent system (toluene+water+propan-2-ol) containing diblock copolymers of poly(styrene-b-2-vinylpyridine-1-oxide). Microemulsions have been shown to form on the water-rich side of the phase diagram, in the region of the phase boundary without polymer. Dynamic light-scattering experiments have led to droplet size values in the region of 100 nm, with the size depending strongly on the propan-2-ol/water concentration, as well as the amount of solubilised toluene in the core. Viscometry experiments have been carried out to measure polymer aggregation numbers in the microemulsion droplets, and interfacial tension measurements have shown that in the absence of propan-2-ol (effectively a cosurfactant) the limiting value of the oil/water interfacial tension, even an saturation adsorption of the copolymer is 20 mNm–1. However, addition of propan-2-ol reduces the interfacial tension to the very low values generall commensurate with microemulsion formation.  相似文献   

20.
The present study evaluates a new method to prepare Cerium oxide (CeO2) nanoparticles by formamide/tri(ethyleneglycol)monododecyl ether (C12E3)/n-octane oil-continuous nonaqueous microemulsion. The effect of the polar phase (formamide/water) on the phase behavior, drop size, and conductivity behavior of the reverse microemulsion were investigated. X-ray diffraction (XRD) and transmission electron microscopy (TEM) were used to characterize the phase and morphology of synthesized CeO2 nanoparticles. It was found that the CeO2 powders synthesized within nonaqueous microemulsions and aqueous microemulisons had an average particle size of 30–50 nm and 15–40 nm, respectively. The experimental results indicate the formation mechanism of CeO2 nanoparticles in formamide nonaqueous microemulsion and aqueous microemulsion is similar, and the formamide nonaqueous microemulsion can be used as nanoreactors for preparation of nanoparticles.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号